A large-size dump truck utilized for construction work and ore transportation, as shown in FIG. 1, comprises a truck body 1 having a base to which are attached front wheels 2 and rear wheels 3. A driver's cab 4 is attached to the front of the truck body. A vessel 5 that is able to lift from its front side. The rear of the vessel protrudes largely backward from the position of the rear wheels 3.
Such a large-size dump truck often runs on a rough road, and therefore, there is a possibility that the dump truck will fall over. In order to protect an operator when the dump truck falls over, as shown in FIG. 1, a protective guard 6 for falling is secured on the truck body 1 between the operation room 4 and vessel 5 for protecting the rear part and upper part of the driver's cab 4. Further, as shown in FIG. 2, there is provided a protective guard 7 for providing protection against falling toward the entire of the driver's cab 4, where the protective guard 7 is secured on the body 1 in one piece with the driver's cab 4.
As explained above, since the rear of the vessel 5 largely protrudes from the position of the rear wheels 3, when the large-size dump truck having the protective guard 6 shown in FIG. 1 runs backward, the rear of the vessel 5 may collide with the driver's cab 4 of another large-size dump truck which follows, as shown in FIG. 3, sometimes causing serious damage.
In the case of the large-size dump truck having the protective guard 7 for falling as shown in FIG. 2, the protective guard 7 prevents the driver's cab 4 from being damaged when the rear of the vessel 5 collides with another one. However, since the protective guard 7 for falling is firmly fastened on A- and B-portions of the truck body 1 using bolts, it is almost true that the driver's cab 4 is directly fixed on the truck body 1, thereby increasing vibration and noise reaching the driver's cab 4. In contrast, the large-size dump truck in FIG. 1 can reduce vibration and noise reaching the driver's cab 4, because it is possible to fix the driver's cab 4 on a C-portion of the truck body 1 via a rubber member.
On one hand, as illustrated in FIG. 4, a collision-protective stopper 9 can be attached to a bumper 8 of the truck body 1, which is able to avoid a collision between the rear of the vessel 5 and the driver's cab 4 of the large-size dump truck which follows, because the collision-protective stopper 9 can be in touch with the rear wheels 3 of a preceding large-size dump truck before the collision. However, such a design increases the overall length of a large-size dump truck, which will become an obstacle to traveling in a narrow area.
Therefore, an object of the present invention is to provide a protective device for the driver's cab front of a large-size dump truck constructed such that, when the rear of the vessel of a preceding dump truck collides with the front of the operation room of a following dump truck, the driver's cab of the following dump truck can surely and safely be avoided from being damaged. The driver's cab can be fixed via a buffer member on the truck body in the same way as the conventional one, so as to reduce vibration and noise, and the large-size dump truck can maintain a small turn radius by excluding a long overall length of the truck body.